Charge bottle for a mass separator



July 7, 1959 P. H. DAVIDSON CHARGE BOTTLE FOR A MASS SEPARATOR Filed Sept. 23, 1948 INVENTOR Pfl/L/P H. DA v/osaw BY ATTORNEY United States Patent Q CHARGE BOTTLE FOR A MASS SEPARATOR Philip H. Davidson, Millbrae, Calif., assignor to the United States of America as represented by the United States Atomic Energy Commission Application September 23, 1948, Serial No. 50,722.

Claims. (Cl. 250-419 This invention relates to improved mass separator charge bottles for containing a dense charge of a chemical compound which is to be vaporized, and to the method of utilizing such improved charge bottles so that the chemical compound is vaporized from the under surface of the charge.

A charge bottle may be described as a receptacle for containing a compound of copper, nickel, lead, or other substance adapted to use in a mass separator; it is inserted into the reservoir of a mass separator source unit, the source having means for vaporizing the said compound. Another example of the use of this invention is in the source unit of a calutron; calutrons are described in great detail in US. Patent No. 2,709,222, which issued on May 24, 1955, to Ernest 0. Lawrence. Such a calutron essentially comprises means for vaporizing a quantity of material containing an element, for example uranium, which is to be enriched with a selected one of its several isotopes; means for subjecting the vapor to ionization within an ionization chamber, whereby the vapor of the element is ionized, causing ions of the several isotopes to be produced; electrical means for segregating the ions from the un-ionized vapor and for imparting motion to the segregated ions along a given path; electromagnetic means for deflecting the ions along curved paths of diiferentradius for each isotope, and means for collecting the ions of the selected isotope to produce a deposit of the element enriched with the selected isotope.

The device for supplying the vapor of a material, such as a compound of uranium, that is to be so treated in a calutron, ordinarily comprises a heated chamber or reservoir into which is inserted the receptacle or charge bottle containing the compound that volatilizes upon heating. Usually the charge bottles are filled with the desired uranium compound in granular form, whereupon they are sealed against the action of ordinary atmosphere and stored until needed for charging the calutron preparatory to operating it. The amount of vaporized material supplied to the ionization chamber of the calutron is regulated by controlling the temperature applied to the reservoir containing the charge bottle; however, with the charge material in a granular form, it has been found by experience that the material cannot be brought quickly to the desired temperature for sublimation so that the vapor therefrom will be furnished to the ionization chamber at the desired rate.

. The method of producing dense, compact masses of a sublimate material, such as certain uranium compounds, and the loading of such compounds into the storage receptacle, or charge bottle, whereby they may be readily utilized as described heretofore, has been more fully set forth in a copending application of Philip H. Davidson, Serial No. 659,715, filed February 19, 1946. The method of operation used in the above-mentioned application for utilization of the loaded charge bottle is as follows: The charge bottle is inserted in the mass separator reservoir so that the vapor from the heated material flows from the upper surface of the charge and through an aperture in the top of the charge bottle and thence through passages to the ionization chamber of the calutron. Uranium compounds may contain as much as 20% of non-volatile residue which i will, during heating of the charge material, form a heavy layer on the uranium compound beneath, thereby seriously reducing the rate of vaporization of the material. This non-volatile material is also carried by the vapor and is deposited on the walls of the vapor passages and ionization chamber of a calutron forming a hard crust thereon and ultimately affecting the efliciency of operation of the device.

Economical operation of a calutron or a mass separator requires that it run for long periods with little or no attention. It is particularly important that the charge should be renewed or replaced as infrequently as possible, since operation must be suspended during replacement and during the time required for pumping out the airlock through which the replacement must be made.

In practice a charge bottle is loaded with a uranium compound sublimed directly into the bottle according to the method set forth in the said co-pending application of Philip H. Davidson, Serial No. 569,715, filed February 19, 1946. After filling, the bottle is sealed against the deleterious action of the atmosphere by a thin metallic foil. When a new charge is required in a calutron, the exhausted bottle is retracted through an air lock and the full one placed in position; the electrical heater connection is then closed so that the charge material is heated to the point of vaporization. At the same time the metallic foil seal melts, venting the bottle to the ionization chamber of the calutron.

It is desirable to control the rate of gas flow of the vaporized material by controlling the amount of heat applied to the charge bottle. Whereas this method is diflicult to apply successfully when the charge is in a granular state, the increased heat conductivity of the solid material renders it a practicable method of control.

A further advantage inherent in the present invention is the containment of the charge material in the top of the bottle, allowing non-volatile material to drop to the bottom of the bottle as vaporization proceeds and thereby preventing the formation of a cake or crust on the evaporating surface.

It is therefore an object of this invention to provide a charge bottle which can be loaded with a compact mass of charge material by subliming directly into the bottle, thereby producing a charge of higher density than could be obtained by ordinary filling operations, thus permitting longer and more economical operation of the mass separator on a single charge.

It is a further object of this invention to provide an improved charge bottle in which the charge material is compacted and contained at the top of the charge bottle, in such a manner that evaporation takes place from the lower surface of the charge material, permitting the nonvolatile portion thereof to fall to the bottom of the charge bottle where it does not form an obstacle to further evaporation.

Still further objects of the invention will become apparent from the specification and accompanying drawings, in which:

Figure 1 is a general assembly of the charge bottle in a preferred form, showing the charge material partially consumed, the non-volatile portion having fallen to the floor of the bottle;

Fig. 2 is a general assembly of an alternate form of the invention;

Fig. 3 is an assembly of another form of the invention;

Fig. 4 is an assembly of a still further form of the invention;

Fig. 5 is a cross-section of Fig. 2 taken on the line 5-5;

Fig. 6-is a cross-section of Fig. 2 taken on the line 6-6;

- Fig-.7 is a cross-section of Fig. 4 taken on the line 7-7 and Fig. 8Vis across-section of Fig. 3 taken on the line 8-8.

Figs. 1, 2, 3, and 4 of the drawing show charge bottles as positioned within the reservoir; the calutron reservoir and heater arrangements are not shown.

Referring now to Fig. l of the drawing, there is shown a charge bottle comprising a generally tubular housing 10, a ring 11 mounted coaxially within the said housing and at the lower end thereof, a lower flange closure 12 for the housing attached to the internal ring ill by screws 13, an upper flange closure 14- hermetically attached as by Welding or soldering to the housing 10, a vapor tube 15 open at each end and hermetically attached to the upper flange closure 14 and extending through the said flange closure and extending in the opposite direction into the volume of the bottle for approximately threequarters of the length of the housing 10. A retainer ring 17 is retained in superposition upon the said upper flange closure by the screws 18 and holds a metal foil 16 in asealing relation across the outer end of the said vapor tube 15 which passes through the charge material 19 disposed in the upper portion of the charge bottle. The arrows 20 generally indicatethe direction of flow of vapor from the saidcharge material.

Although the foregoing sets forth a preferred embodiment of the invention, permitting as it does the use of such non-corrosive materials as nickel, stainless steel, or chromium in the fabrication of the charge bottle, yet it may in some cases be desirable to have the outer wall fabricated of a cheaper material, or of such a material as copper for more efiicient conduction of the heat used to sublime the charge. An easily. corrodible material such as copper may. not be permitted to contact the charge material, and therefore to overcome this condition there is provided a charge bottle as illustrated in Fig. 2 of the drawing.

5 Referring now to Fig. 2, there is shown a charge bottle comprising a generally tubular housing 10, an upper flange closure 21 hermetically attached as by welding or soldering to. the said housing, and provided with a plurality of apertures 22 for passage of vapor and a central aperture 23 through which passes a screw 24. The said screw extends in an axial and downward direction through the outer housing 10 and into engagement with the threaded wall of a cooperating recess provided in a central boss of the lower flange closure 25. Disposed within the outer housing 10 is a cartridge containing compacted charge material 19 and preferably formed as a re-entrant glass. cylinder 26, the re-entrant section being directed downward and having a length approximately threequarters of that of the said housing. The said re-entrant glass cylinder isnominally of the same outer diameter as the internal diameter of the said housing, thereby providing a close fit for facilitating heat transfer. The l e-entrant section of the said glass cylinder is open at both ends and issurrounded by the compacted mass of the charge material 19 almost to its lower end, the said:

charge material being thus held in the upper end of the charge bottle. The arrows 26 show the general direction of flow of vapor from the said charge material. The upper end of the charge bottle is sealed by the metal foil 16 held by the retainer ring 17 and the screws 18 as in the previously recited embodiment.

Although the embodiments shown in Figs. 1 and 2 are successful forms of the invention, it is desirable when using certain types of charge material to provide means for. retaining such material in the top of the bottle if the action of the vaporizing heat should melt it loose from the walls, Therefore there is provided a charge bottle of the form shown in Fig. 3'.

.Referring more particularly now to Fig, 3, there is shown a charge bottle as in Fig. 1, but with the outer generally tubular housing 27 hearing a plurality of inwardly projecting radial prongs 28 projecting into the mass of charge material 19 in such fashion that they provide adequate support to retain the charge material in the upper part of the charge bottle.

It is equally possible to support the charge material by providing the central vapor tube with prongs, and a charge bottle made in this way is cheaper to construct because of its greater ease of assembly. Accordingly, there is provided a charge bottle of the formshownin Fig. 4.

Referring now to Fig. 4, there is shown a charge bottle of the same general form as shown in Figs. 1 and 3, but with the vapor tube 29 bearing a plurality of outwardly projecting radial prongs 30 attached at one end to the outer surface of the said vapor tube and projecting into the mass of charge material 19 in such fashion that adequate support is provided to the said charge material.

While there has been described what is at present considered to be the preferred embodiment of the invention, and three other embodiments having special characteristics, it will be understood that various further modifications may be made therein and it is intended to cover in the appended claims all such modifications as fall within thetrue spirit and scope of the invention.

What is claimed is:

1. A charge bottle for retaining the evaporative source material withina mass separator, comprising a vertically disposed cylindrical portion, a closure hermetically sealingthe, lower open end of said portion, an inner re-entrant cylindrical'portion and extending axially and downwardly into the same from the upper end thereof, an apertured closure for said upper end, a heat-fusible wall for sealing said apertured closure, and evaporative source material in the form of a chemical compound compacted within the upper annular portion of said charge bottle formed I by saidire-entrant cylindrical portion, said chemical compound surrounding said re-entrant portion, whereby vapor from said chemical compound will pass outwardly from said charge bottle through said apertured closure.

2. A charge bottle for a mass separator comprising a vertically disposed cylindrical portion, a removable closure sealing the lower end of said portion, an apertured closure for the upper end of said portion, a removable apertured plate mounted on said apertured closure, a heat-fusible wall disposed between said plate and said apertured closure for hermetically sealing said charge bottle, and an inner re-entrant cylindrical cartridge containing compacted evaporative source material in the an nular portion thereof, said cartridge snugly fitting into said vertically disposed cylindrical portion directly be-,

7 neath said apertured closure, whereby vapor from said source material will pass upwardly through said inner re-entrant cylindrical cartridge and outwardly through the'apertures of said closure upon heating'of said charge bottle in a mass separator.

3. A charge bottle for retaining the evaporative source material withina mass separator, comprising avertically disposed cylindrical portion, a removable closure sealing thelower end of said portion, an inner re-entrant cylindrical portion mounted in rigid relationship to said vertically disposed cylindrical portion and extending axially and downwardly into the same from the upper end thereof, said re-entrant cylindrical portion bearing prongs radially attached thereto and extending horizontally toward the inner wall of said vertically disposed cylindrical portion and adapted to support said source material within amass separator asin claim 3, bearing.

a chemical compound compacted within the upper annular portion of said charge bottle formed by said reentrant prong-bearing cylindrical portion, said chemical compound surrounding said re-entrant portion.

5. A charge bottle for retaining the evaporative source material within a mass separator, comprising a vertically disposed cylindrical portion bearing prongs radially attached to the inner surface thereof and extending horizontally toward the vertical axis of said vertically disposed cylindrical portion and adapted to support said source material in the upper part of said vertically disposed cylindrical portion, a removable closure sealing the lower end of said portion, an inner re-entrant cylindrical portion mounted in rigid relationship to said vertically disposed cylindrical portion and extending axially and downwardly into the same from the upper end thereof, an apertured closure for said upper end for permitting the vapor from said source material to pass outwardly from said charge bottle, and a heat-fusible wall for sealing said closure aperture.

6. A charge bottle for retaining the evaporative source material within a mass separator as in claim 5, bearing a chemical compound compacted within the upper annular portion of said charge bottle formed by said reentrant cylindrical portion, said chemical compound surrounding said re-entrant portion and supported by said prongs.

7. A charge bottle for retaining the evaporative source material within a mass separator, comprising a vertically disposed cylindrical portion, a removable closure sealing the lower end of said portion, an inner re-entrant cylindrical portion mounted in rigid relationship to said vertically disposed cylindrcal portion and extending axially and downwardly into the same from the upper end thereof, said re-entrant cylindrical portion bearing prongs radially attached thereto and extending horizontally toward the inner wall of said vertically disposed cylindrical portion and adapted to support said source material in the upper part of said vertically disposed cylindrical portion, an apertured closure for the upper end of said vertically disposed cylindrical portion for permitting the vapor from said source material to pass outwardly from said charge bottle, a removable apertured plate mounted on said apertured closure, and a heat-fusible Wall disposed between said plate and said apertured closure for sealing said source material and vapor within said charge bottle.

8. A charge bottle for retaining the evaporative source material within a mass separator as in claim 7, bearing a chemical compound compacted within the upper annular portion of said charge bottle formed by said re-entrant prong-bearing cylindrical portion, said chemical compound surrounding said re-entrant portion.

9. A charge bottle for retaining the evaporative source material within a mass separator, comprising a vertically disposed cylindrical portion bearing prongs radially attached to the inner surface thereof and extending horizontally toward the vertical axis of said vertically disposed cylindrical portion and adapted to support said source material in the upper part of said vertically disposed cylindrical portion, a removable closure sealing the lower end of said portion, an inner ire-entrant cylindrical portion mounted in rigid relationship to said vertically disposed cylindrical portion and extending axially and downwardly into the same from the upper end thereof, an apertured closure for said upper end permitting the vapor from said source material to pass outwardly from said container, a removable apertured plate mounted on said apertured closure, and a heat-fusible wall disposed between said plate and said apertured closure for sealing said source material and vapor within said charge bottle.

10. A charge bottle for retaining the evaporative source material within a mass separator as in claim 9, bearing a chemical compound compacted within the upper annular portion of said charge bottle formed by said reentrant cylindrical portion, said chemical compound surrounding said re-entrant portion.

References Cited in the file of this patent UNITED STATES PATENTS 2,200,475 Legeler May 14, 1940 2,221,467 Bleakney Nov. 12, 1940 2,386,189 Bagley Oct. 9, 1945 

